The objectives of the past year included investigations on: 1) The influence of meal frequency on the chicken and dog. 2) The production of antibodies to rat liver malic enzyme and tests of antibody specificity in several species. 3) The effect of meal frequency on energy and nitrogen metabolism. Meal-fed chickens exhibited a greater rate of hepatic fatty acid synthesis than did ad libitum fed chickens. Antibodies to rat liver malic enzyme react with rat and mouse adipose tissue malic enzyme but not to chicken, rabbit, dog or lamb adipose tissue or liver malic enzyme. Nitrogen balance in the rat was not influenced by pattern of eating.